The present invention relates to the decoration of articles such as bottles, and more particularly to decoration of articles by means of heat transfer labelling.
Systems using heat transfer labels are widely employed to decorate bottles and similar articles. The type of which the present decorating apparatus is an example includes input and output conveyors for feeding the object to be labelled; a turret for sequentially positioning the bottles at a labelling station; and a deck which includes a feed mechanism for transporting labels supported by a carrier strip to the labelling station as well as a device for pressing the label against an adjacent bottle at the labelling station. Examples of such systems appear in U.S. Pat. Nos. 2,981,432; 3,036,624; 3,064,714; 3,208,897; 3,321,448; 3,261,734; 3,313,667; 3,709,755; and 3,861,986.
These prior art decorators are generally suitable for the user with a high volume of production, for whom the cost of the decorator is of lesser importance as compared with production rates. Such a user places relatively little emphasis on the ease with which a decorator may be adapted to articles of various shapes and sizes. These prior art decorators are not satisfactory, however, for the user with small production runs for whom machine cost and adaptability is of paramount importance. Compact design and ease of operation are also primary considerations for this user.
The label carrier webs in these prior art devices typically include a series of regularly spaced punch holes to allow the fitting of the web onto a sprocket drive roll which establishes a basic transport speed for the web. While this is a generally viable transport method, it suffers certain practical disadvantages. Suitable punching equipment represents a significant expense. The punching of the web weakens it, and requires more expensive paper for a given application than would be required without punching. In addition, driving the carrier strip at the punch holes provides less control than would be available if the entire width of the web were used. Greater control over web transport in turn allows enhanced label transfer quality.
The carrier web transport in decorating apparatus of this type advantageously includes some means for alternately accelerating and retarding the basic carrier web speed (established by the drive roll) in the area of label transfer. This is necessary to ensure that the web will be advanced essentially only during an actual transfer, thus allowing a close spacing of the labels on the carrier web. In the above prior art devices, this function was generally performed by winding the web around two shuttle rolls straddling the labelling site, which shuttle rolls were appended to a reciprocating slide. This method of intermittent web transport allows only limited control over the web advance, which may present a problem in low speed and manual decorating applications.
Commercially acceptable decorating apparatus for articles such as bottles should be adjustable to allow the placement of the transfer label at any height on the bottle surface that the user may specify. Prior art decorators allow a certain leeway in the height of the sprocket drive wheel, but this is insufficient to assure a suitable range of label locations. Such devices may therefore additionally require a raising or lowering of the turret bases for holding articles. A related problem is that of slanted bottle surfaces (such as conical surfaces). Proper label transfer onto such surfaces entails considerable design changes in the turrets of these prior art decorators (see, for example, U.S. Pat. No. 3,313,667).
Accordingly, it is a primary object of the invention to provide compact, low-cost decorating apparatus. A related object of the invention is to achieve a machine with change-over features, to allow economical utilization of such apparatus in low volume production runs.
Another object of the invention is the inclusion in the decorator of an improved carrier web transport. A related object is the elimination of need for sprocket holes in the carrier web. it is a further related object of the invention to lower costs to the user by removing the need for punching equipment and allowing the use of less expensive carrier web material. Another related object is an increased control over web transport, with commensurate improvement in label transfer quality.
It is a further object of the invention to provide intermittent web transport with improved control characteristics. A related object is the incorporation of web transport control apparatus which will be suitable for low-speed and manual decorating applications.
Yet another object of the invention is the allowance of wide variation in vertical label placement and angle of label application. It is a related object to avoid the necessity for design changes in the turret in providing such flexibility.